The present application claims priority under 35 U.S.C. xc2xa7119 of German Patent Application No. 198 51 593.6, filed Nov. 9, 1998, the disclosure of which is expressly incorporated by reference herein in its entirety.
1. Field of the Invention
The invention concerns a process for handling a material web, such as a paper or cardboard web, in which the material web is moved at least in stretches with at least one continuous circulating belt, such as a wire or a felt belt, in a direction of circulation.
2. Discussion of Background Information
In the wire and/or press section of a paper machine, premature wear may occur on or near the edges of the circulating wire or felt belts used therein. Similarly, marking and soiling occur on the wire or felt belts which results in a short service live.
In a wet press known from DE 43 01 651 C1, the path of the belt is repeatedly extended and/or shortened on one outer edge relative to the other outer edge.
In a belt positioning arrangement known from DE 37 35 202 A1, continuous position detection for controlling the edges of moving webs, e.g., paper webs, drying felts, wires, or the like, is accomplished by continuously moving a position sensor along a circular path crossing the respective web edge twice.
In a paper machine known from U.S. Pat. No. 5,614,063, deviations in movement transverse to the circulation direction of an endless belt are detected by edge detectors, which emanate signals used to move the circulating belt back into its proper position, when necessary.
In an arrangement for guiding a continuous felt known from DE 40 11 796 A1, the belt is guided by a repeatedly inclined compensator roller and a regulating roller, both of which are automatically pivoted such that a monitored edge of the belt remains in a pre-specified plane. The belt is also braced, on its two edges, by the compensator roller.
The disclosures of the aforementioned patents are expressly incorporated by reference herein in their entirety.
The invention disclosed herein improves the process as well as the type of device described in the introduction by virtually eliminating markings and soiling in and around the edge of an endless belt, which results in longer belt service lives.
Specifically, this is done by repeatedly moving an endless belt generally transverse to the direction of circulation. Preferably, the belt is moved only periodically in the transverse direction.
The present invention may be embodied in three ways. Transverse movement of the endless belt may be effectuated solely by the control device or solely by the master control unit, or the traverse movement may be effectuated by the control device and the master control unit in cooperation.
In an embodiment of the process according to the invention wherein the control device and the master control unit cooperate, a belt travel sensor monitors the position of the belt, and, when necessary, the belt is adjusted accordingly in the transverse direction. To adjust the belt""s position, sensor signals generated by the belt travel sensor are fed to a master control unit which controls the transverse movement of the belt.
In this invention, the belt travel sensor, which monitors the belt edges, may be a belt travel feeler or the like.
Further, the belt may be moved stepwise in the transverse direction. In certain applications, however, it is preferable for the belt to be moved continuously in the transverse direction.
According to an embodiment of the invention, the belt travel sensor may be driven in a linear manner, thereby causing the transverse movement of the belt, by an activation device which is controlled by an associated control device.
In the invention disclosed herein, the activation device can include at least one cylinder/piston unit. The cylinder/piston unit operates in only one direction and has a spring reset.
The distance of the transverse movement of the belt is preferably adjustable. Additionally, the travel time of the transverse movement of the belt may also be adjustable.
In an embodiment of the device according to the invention, the control device associated with the activation device includes at least one pressure regulator with a motorized adjustment.
The belt travel sensor may also be a pendulum feeler or the like.
The belt may be a wire or a felt belt. The invention is thus applicable both in the wire and in the press section of a respective paper making machine. It is also possible for a plurality of wire or felt belts to be moved transverse to the direction of circulation.
According to the invention, there is disclosed a process for handling a material web. The process includes moving the material web, at least in stretches, along with at least one circulating endless belt in a circulation direction and monitoring the movement of the edge of the at least one circulating endless belt. The process further includes driving repeatedly the circulating endless belt in a direction generally transverse to the circulation direction.
In the process disclosed herein, the belt may be either one of a wire belt or a felt belt, and the material web may be one of paper or cardboard.
Additionally, the at least one circulating endless belt can be moved periodically in the transverse direction.
According to the invention, the process further includes monitoring the position of the at least one circulating endless belt in the transverse direction by way of a belt travel sensor and driving the at least one circulating endless belt in the transverse direction to generate linear transverse movement of the at least one circulating endless belt.
The belt travel sensor may also be a belt travel feeler. In the invention, the belt travel sensor can be used for belt edge detection.
Additionally, the monitored position of the at least one circulating endless belt is fed to a master control unit for controlling the transverse movement of the at least one circulating endless belt.
With respect to movement of the circulating endless belt, it may be either moved stepwise in the transverse direction, or it can be moved continuously in the transverse direction.
According to the invention, the process further includes the at least one circulating endless belt being driven in the transverse direction, the magnitude of which is determined by the actuation device and the associated control device acting together. Additionally, the process includes the at least one circulating endless belt being driven in the transverse direction, the movement magnitude of which is determined solely by the master control device. Further, the process includes the at least one circulating endless belt being driven in the transverse direction, the movement magnitude of which is determined by a master control device in cooperation with an actuation device and an associated control device.
According to the invention, there is provided a device for handling a material web is provided. The device includes at least one circulating endless belt for moving the material web along, at least in stretches, in a circular direction, and at least one belt travel sensor for monitoring the position of the at least one circulating endless belt and repeatedly moving the at least one circulating endless belt generally transverse to the circulation direction. The invention further includes an activation device, for moving the sensor and an associated control device, for actuating the activation device.
In the device disclosed herein, the material web may be either one of paper or cardboard.
In the invention, the at least one belt travel sensor is provided for moving the at least one continuous belt periodically in the transverse direction. The device further includes a master control unit, which cooperates with the at least one belt travel sensor, which monitors the position of the at least one circulating endless belt in the transverse direction, to drive the at least one circulating endless belt in the transverse direction.
According to the invention, the magnitude of the transverse movement of the endless circulating belt is determined by cooperation between the activation device for moving the sensor and the associated control device for actuating the activation device.
In the device disclosed herein, sensor signals are generated by the at least one belt travel sensor, the signals being fed to the master control unit for determining the transverse movement of the at least one circulating endless belt. Alternatively, the master control unit may cooperate with the activation device for moving the sensor and the associated control device for actuating the activation device to generate the transverse movement of the circulating endless belt.
Additionally, the device includes a distance adjustment mechanism for adjusting the distance of the traverse movement of the at least one circulating endless belt, and a time adjustment mechanism for adjusting the travel time of the traverse movement of the at least one circulating endless belt. The mechanisms may move the at least one circulating endless belt stepwise in the transverse direction, or it may be moved continuously in the transverse direction.
In the present invention, the at least one belt travel sensor may be a belt travel feeler, and the at least one belt travel sensor monitors the location of the edge of the circulating endless belt. Further, the at least one belt travel sensor may be a pendulum feeler.
According to the invention, the associated control device includes a pressure regulator and a motorized adjustment device for the regulator. The pressure may be either hydraulic or pneumatic.
In the device disclosed herein, the activation device, which includes at least one cylinder/piston unit, moves the at least one belt travel sensor linearly. Additionally, the at least one cylinder/piston unit includes a piston acting in one direction and a spring reset for acting in the other direction.
According to the invention described herein, there is disclosed a device for handling a material web. The device includes at least one circulating endless belt for moving the material web along, at least in stretches, in a circular direction, and a master control unit for determining the transverse movement of the circulating endless belt. Additionally, the device includes at least one belt travel sensor for monitoring the position of the at least one circulating endless belt and repeatedly moving, in cooperation with the master control unit, the at least one circulating endless belt generally transverse to the circulation direction, and an activation device, for moving the sensor. The device further includes an associated control device, further comprising a pressure regulator and associated motorized adjustment device, for actuating the activation device. In the invention, sensor signals are generated by the at least one belt travel sensor, the signals being fed to the master control unit for determining the transverse movement of the at least one circulating endless belt.
Examples of a pendulum feeler and cylinder/piston unit are described in the HDU Autoguide Assembly, Paper and Board Machine Clothing Always under control, Product Information, VOITH SULZER PAPER TECHNOLOGY (April; 1999)(in English), which is incorporated herein by reference. Additional details are described in Bandlaufregler HDU6, VOITH SULZER PAPER TECHNOLOGY, (Sep. 15, 1999), which is incorporated herein by reference.
Other exemplary embodiments and advantages of the present invention may be ascertained by reviewing the present disclosure and the accompanying drawing.